文章基本信息

标题：Sensory determinants of behavioral dynamics in Drosophila thermotaxis
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作者：Mason Klein ; Bruno Afonso ; Ashley J. Vonner 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：2
页码：E220-E229
DOI：10.1073/pnas.1416212112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceA previously unidentified set of thermosensory neurons embedded in the olfactory organ of the Drosophila larva is shown to be required to drive the animal up temperature gradients toward preferred environments. Optogenetics and optical neurophysiology reveal efficient sensory encoding of both favorable (warming) and unfavorable (cooling) stimuli for distinct components of thermotactic strategy by this one set of neurons. Cooling-evoked activation is used to curtail forward movements in unfavorable directions; warming-evoked deactivation is used to orient new forward movements in favorable directions during turns. Our results pinpoint the locus of thermosensory perception for cool-avoidance behavior in the larva and define how downstream circuits use thermosensory perception to organize navigational behavior. Complex animal behaviors are built from dynamical relationships between sensory inputs, neuronal activity, and motor outputs in patterns with strategic value. Connecting these patterns illuminates how nervous systems compute behavior. Here, we study Drosophila larva navigation up temperature gradients toward preferred temperatures (positive thermotaxis). By tracking the movements of animals responding to fixed spatial temperature gradients or random temperature fluctuations, we calculate the sensitivity and dynamics of the conversion of thermosensory inputs into motor responses. We discover three thermosensory neurons in each dorsal organ ganglion (DOG) that are required for positive thermotaxis. Random optogenetic stimulation of the DOG thermosensory neurons evokes behavioral patterns that mimic the response to temperature variations. In vivo calcium and voltage imaging reveals that the DOG thermosensory neurons exhibit activity patterns with sensitivity and dynamics matched to the behavioral response. Temporal processing of temperature variations carried out by the DOG thermosensory neurons emerges in distinct motor responses during thermotaxis.
关键词：navigation ; reverse correlation ; temperature ; calcium imaging ; voltage imaging